Struct MenuBarState 

pub struct MenuBarState { /* private fields */ }

Which label’s popup is open (if any) for a MenuBar, plus that popup’s own MenuState.

A menu bar has at most one open popup at a time, so this wraps a single MenuState rather than one per label: switching which label is open always goes through open, which closes whatever was open first. Holds no reference to the bar’s own titles/rows, the same design MenuState itself uses: every method that needs to know a label’s row count takes len and a selectable predicate rather than a concrete row type, so this stays reusable across whatever row type a call site’s MenuBar uses.

open_label is gated on MenuState::is_open rather than tracked as an independent flag: MenuState::handle_event (Escape) and Menu::show (an outside click, or a row activation) already close the inner MenuState on the caller’s behalf, and gating the getter this way means those paths automatically clear which label reads as open too, with nothing to keep in sync by hand.

Examples

use retroglyph_ui::state::MenuBarState;

// Two labels, each with one selectable row.
let selectable = |_: usize| true;

let mut state = MenuBarState::new();
state.open(0, 1, selectable);
assert_eq!(state.open_label(), Some(0));

// Hovering another label while one is open switches to it (see `MenuBar::show`); modeled
// here directly as another `open` call.
state.open(1, 1, selectable);
assert_eq!(state.open_label(), Some(1));

state.close();
assert_eq!(state.open_label(), None);

Implementations

impl MenuBarState

pub const fn new() -> Self

A closed menu bar: no label open.

pub const fn open_label(&self) -> Option<usize>

The label whose popup is currently open, if any. See the type docs for why this is derived from MenuState::is_open rather than stored independently.

pub const fn menu(&self) -> &MenuState

The open popup’s own state, for driving it through Menu::show.

pub const fn menu_mut(&mut self) -> &mut MenuState

Mutable access to the open popup’s own state, for driving it through Menu::show.

pub fn open( &mut self, label: usize, len: usize, selectable: impl Fn(usize) -> bool, )

Open label’s popup, selecting its first selectable row among 0..len (skipping any leading separators/labels), closing whatever label’s popup was open first. A no-op (closes without opening the new label) if label has no selectable row at all, mirroring MenuState::open.

pub const fn close(&mut self)

Close whichever label’s popup is open. A no-op if none is.

pub fn toggle( &mut self, label: usize, len: usize, selectable: impl Fn(usize) -> bool, )

close if label’s popup is already open, otherwise open it.

pub fn hover( &mut self, label: Option<usize>, len: usize, selectable: impl Fn(usize) -> bool, )

Switch to label’s popup, but only on the frame label first differs from what hover resolved to last time this was called – a no-op both while a pointer sits still over the same label across frames, and while no popup is open at all (a cold hover; see MenuBar’s docs). See the hover field’s own doc comment for why this edge-triggering, rather than a fresh “is label different from what’s open” check every frame, is what keeps this from fighting a MenuBar::handle_event keyboard switch.

Trait Implementations

impl Clone for MenuBarState

fn clone(&self) -> MenuBarState

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for MenuBarState

impl Debug for MenuBarState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for MenuBarState

fn default() -> MenuBarState

Returns the “default value” for a type.

impl Eq for MenuBarState

impl PartialEq for MenuBarState

fn eq(&self, other: &MenuBarState) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for MenuBarState